In general, ejaculation less than 2 minutes after the start of sex can be initially judged as premature ejaculation. In addition, premature ejaculation is generally divided into three grades: mild, moderate and severe. Mild premature ejaculation usually refers to ejaculation after the penis is inserted into the vagina for 1-3 minutes and is able to pump more than fifteen times. Moderate premature ejaculation usually refers to ejaculation after the penis has been inserted into the vagina for less than one minute and the penis is able to pump five times in the vagina. Severe premature ejaculation usually refers to ejaculation before or just after penile insertion into the vagina, as well as complete inability to cooperate with the sexual partner to control ejaculation during conjugal life with the partner.